Struct ObjectVersionStore 

pub struct ObjectVersionStore {
    pub config: VersionStoreConfig,
    pub versions: HashMap<u64, OvsObjectVersion>,
    pub branches: HashMap<String, VersionBranch>,
    pub next_version: u64,
    pub total_bytes: u64,
    pub deleted_versions: u64,
}

Versioned object store with branch management and configurable GC.

Lifecycle

1. Create with ObjectVersionStore::new.
2. Commit new content with ObjectVersionStore::put or ObjectVersionStore::put_on_branch.
3. Retrieve historical content with ObjectVersionStore::get.
4. Create branches with ObjectVersionStore::create_branch and merge them back with ObjectVersionStore::merge_branch.
5. Run GC explicitly with ObjectVersionStore::gc or let put trigger it automatically when max_versions is reached.

Fields

config: VersionStoreConfig

Runtime configuration.

versions: HashMap<u64, OvsObjectVersion>

Live version storage, keyed by version number.

branches: HashMap<String, VersionBranch>

Branch registry, keyed by branch name.

next_version: u64

Counter for the next version number to assign.

total_bytes: u64

Cumulative byte count for all live versions.

deleted_versions: u64

Total number of versions that have been garbage-collected.

Implementations

impl ObjectVersionStore

pub fn new(config: VersionStoreConfig) -> Self

Create a new store and initialise the “main” branch at version 0.

Version 0 is a sentinel – it is not inserted into versions. The “main” branch’s head_version starts at 0, meaning “no versions yet”.

pub fn put(&mut self, data: Vec<u8>, tags: Vec<String>, now: u64) -> u64

Commit data on the “main” branch and return the new version number.

If the version count would exceed config.max_versions, GC is run before inserting. CID is computed as the FNV-1a 64-bit hex hash of data.

pub fn put_on_branch( &mut self, branch: String, data: Vec<u8>, tags: Vec<String>, now: u64, ) -> Result<u64, VsError>

Commit data on a named branch and return the new version number.

Returns VsError::BranchNotFound if the branch does not exist.

pub fn get(&self, query: VersionQuery) -> Result<&OvsObjectVersion, VsError>

Retrieve a version according to the given VersionQuery.

pub fn create_branch( &mut self, name: String, from_version: u64, now: u64, ) -> Result<(), VsError>

Create a new branch starting at from_version.

Errors

• VsError::BranchAlreadyExists if name is taken.
• VsError::VersionNotFound if from_version is not in the store.
• VsError::MaxBranchesReached if the branch limit is hit.

pub fn merge_branch( &mut self, source: &str, target: &str, now: u64, ) -> Result<u64, VsError>

Merge the head of source into target by creating a new version on target that is a copy of the source head, with parent_version set to the source head version number.

Returns the new version number.

pub fn history(&self, branch: &str) -> Result<Vec<&OvsObjectVersion>, VsError>

Walk the parent-version chain from the head of branch and return versions in reverse-chronological order (newest first).

pub fn reachable_from_heads(&self) -> HashSet<u64>

Compute the set of version numbers reachable from any branch head via parent_version links.

pub fn gc(&mut self) -> usize

Run garbage collection according to config.gc_policy.

Returns the number of versions deleted.

pub fn version_count(&self) -> usize

Number of live versions currently in the store.

pub fn total_size_bytes(&self) -> u64

Total bytes occupied by all live version payloads.

pub fn stats(&self) -> VsStats

Return a statistics snapshot.